An image forming apparatus such as printer, copier, facsimile has a developing unit to develop a toner image with a developing agent having toners and carriers.
Toners are consumed as image forming progresses, thereby the image forming apparatus includes a toner container (e.g., toner bottle and toner cartridge) to store toners in the image forming apparatus, and a toner refill unit supplies toners to the developing unit from the toner container.
When the toner container becomes empty, the toner container is replaced from the image forming apparatus, and a new toner container is installed in the image forming apparatus. Such toner containers are made of hard material (hereinafter, hard casing), in general.
However, such hard casing has drawbacks in terms of recovery cost because of the relatively large volume of the hard casing. Thereby some toner containers have been changed to a softer casing, which has a relatively smaller volume.
However, such softer casing having flexibility is not preferable from the viewpoint of keeping the toner container in a predetermined position when the toner container is installed in the image forming apparatus. Thereby, instead of installing a softer casing directly in the image forming apparatus, a hard box encasing a softer casing may be installed in the image forming apparatus.
Furthermore, some toners still remain in the toner container even if a toner end (i.e., toner empty) condition is detected in the image forming apparatus. Generally, it is difficult to completely discharge toners from the toner container.
In order to reduce the amount of toners remaining in the toner container after the toner end (i.e., toner empty) condition, the toner discharge port of the toner container can be preferably made larger.
However, a larger toner discharge port may be more likely to cause drawbacks such as toner scattering and toner leakage.
When an empty toner container is removed from the image forming apparatus, the toner discharge port is required to be closed to prevent toner related contamination such as toner scattering and toner leakage. If the toner discharge port is not closed completely, such toner related contamination may occur.
Therefore, the smaller the opening area of the toner discharge port of the toner container, the easier it is to prevent the occurrence of the toner related contamination.
A new toner container is required to be in a toner refillable condition by opening the toner discharge port when the new toner container is installed in a predetermined position in the image forming apparatus.
Therefore, the smaller the opening area of the toner discharge port of the toner container, the easier it is to open the toner discharge port when the toner container is installed in a predetermined position.
However, if the opening area of the toner discharge port of the toner container is too small, a larger amount of toners may be more likely to remain in the toner container at toner end (i.e., toner empty) condition.
In general, the toner container is replaced by a user, thereby the user feel some degree of unhappiness if a larger amount of toners still remain in the toner container when the user removed the toner container from the image forming apparatus. In such case, the user may install the retrieved toner container again in the image forming apparatus because the user may judge that the toner container is not empty.
A related art container employs an oscillating mechanism as a toner refill unit to refill toners stably and to reduce the amount of toners remaining in the toner container at toner end (i.e., toner empty) condition.
Such oscillating mechanism oscillates a toner container and suddenly stops the toner container so that toners in the toner container can move to a toner discharging port with inertia force. With such configuration, toners can be discharged from the toner discharging port more easily, thereby toners remained in the toner container may be reduced at a toner end (i.e., toner empty) condition.
In such oscillating mechanism, the toner container is required to be firmly fixed to the oscillating mechanism because the toner container is oscillated by the oscillating mechanism.
However, if the toner container employs a softer casing, such softer casing may have difficulty in being firmly fixed to the oscillating mechanism, although the softer casing is preferable from a viewpoint of cost such as distribution costs and recovering cost.
On one hand, however, if the toner container is fixed to the oscillating mechanism too firmly, the attachment/detachment work of the toner container in an image forming apparatus may become difficult.
Furthermore, even if the toner container is fixed to the oscillating mechanism firmly, toners may not be discharged effectively from the toner discharge port if toner fluidity deteriorates (e.g., clogging occurs).
In order to cope with such drawbacks on toner discharge effectiveness, the opening area of the toner discharge port is preferably set to be larger for effective toner discharge.
However, the larger the opening area of the toner discharge port of the toner container, the harder it is to prevent the occurrence of toner related contamination such as toner scattering and toner leakage when the toner container is attached/detached in the image forming apparatus.
From the viewpoint of stable toner discharge from the toner container, a larger toner discharge port is preferable, however, from the viewpoint of preventing toner related contamination, a smaller toner discharge port is preferable.
Furthermore, toner related contamination such as toner scattering and toners leakage may occur for a conventional toner container if a user opens a toner discharge port of the toner container unintentionally before the toner container is installed in an image forming apparatus.
In order to prevent such unintentional opening of the toner discharge port of a toner container, the toner discharge port of the toner container can be sealed with a seal member.
However, a user may forget to peel off the seal member from the toner container, and install such toner container in an image forming apparatus without peeling off the seal member.